This proposal is for continuation of research in the natural history, treatment and epidemiology of childhood cancer. As a cooperative member of Children's Cancer Study Group A, this institution presently has over 130 children with acute leukemia and 230 with solid tumors on protocol studies. Such studies in leukemia deal primarily with the induction of remission and marked prolongation of remission maintenance with the utilization of intensification phase in which the central nervous system is treated prophylactically and supportive therapy both medical and social. Similarly, studies of children with Wilms' tumor and neuroblastoma, rhabdomyosarcoma, bone tumors, brain tumors and other less common malignancies are underway. A close working relationship with the Adult Leukemia Center under Dr. E. Donnall Thomas, including exchange of professional personnel continues and further bone marrow transplantation in children with leukemia have been done. Corroborative studies with Drs. Karl-Erik and Ingegerd Hellstrom and I. Bersntein of our department in determination of tumor specific antigens in patients with neuroblastoma and potential future immunotherapy are continuing. In addition, collaboration locally with Dr. William C. Dolowy will continue now in the development of a new enzyme, L- glutaminase.